Application Of Controlled Source Audio-frequency Magnetotellurics In The Geothermal Field Of Dalian

As a green energy, geothermal resources exploitation and utilization of theextensive attention by people gradually. Usually buried deep geothermal resources,mining the risk is very big. In order to improve the efficiency and reduce the cost,reduce investment risks, develop geothermal resources must be carried out before thegeological survey, geophysical exploration is geothermal investigation is one of theimportant means. The underground hot water can make heat reservoir a resistivityreduce, low resistance abnormality is an important symbol of identifying geothermalresources, so ever in geothermal investigation, dc resistivity method has been dominant.Dc resistivity method work efficiency is low, the exploration depth in relatively shallow,by use of large restrictions. At present the depth of geothermal resource development ismore and more big, mostly mining depth has more than2,000meters. Along with thedepth is increased, the surface observed caused by underground hot water is more andmore small, the resistivity differences make it difficult to observed caused bygeothermal changes the anomalous, so deep geothermal investigation is the main taskof the reservoir exploration of heat distribution of stratum and geological structures.Of controlled source audio-frequency magnetotelluric sounding grounding wireswith limited long for field source, in a certain distance from the field source center inelectrical, magnetic parameters and observation of a kind of electromagnetic soundingmethod. This method adopts fixed source observation, exploration depth is oppositebigger, is the deep geothermal exploration main means.This research using typical geothermal field experiment research, the researchmethods of controlled source audio-frequency magnetotelluric sounding method intypical geothermal field technique and explain technology on.Using the resistivity two-dimensional and three-dimensional space distributionsituation, the groundwater source channel, occurrence space position, inference andcover layer heat store may occurrence position; Using research resistivity2d,3d spacedistribution and indirect judgment geothermal resources guide method and techniquestore geothermal structure.Through the research shows that: certain conditions, of controlled source audio-frequency magnetotelluric sounding method better able to bear fractured zonesof geothermal field of fault exploration work and resistivity anomaly can better reflectgeothermal storage conditions and the distribution of thermal storage space. At presentgeothermal field exploration main task is to find out geothermal field generatedenvironment and hot store storage space. With the deepening exploration depth, miningrisk increased, the surface with the anomaly information collection to the validity of themethod of weakened gradually some reduced significantly, and exploration difficultywill also increase, therefore, the use of controlled source audio-frequencymagnetotelluric sounding method, combining with known geological explorationgeothermal and other related material for comprehensive research conducted geologicalinterpretation, reasonable, reduces the risk of investment, the key is geothermal fieldexploration.